1. Field of the Invention
The present invention relates to a distance measuring apparatus, or range finder.
2. Related Background Art
As a conventional distance measuring apparatus or range finder, there has been proposed a one that disposes a transmitting optical system and a receiving optical system completely independently (for example, see Japanese Patent Application Laid-Open No. 2002-350543).
However, the conventional laser range finder that makes the transmitting optical system and the receiving optical system completely independent has been disadvantageous for making it compact.
Although it has been technically possible to make it compact by making the transmitting optical system and the receiving optical system common, sufficient measurement light amount has not been secured and it has been difficult to make the measuring distance longer.
Moreover, with configuring the distance measuring apparatus or range finder as described above, since the transmitting optical path and the receiving optical path are disposed close together, a portion of light emitted from the light source is mixed into the optical path of the receiving optical system inside of the range finder to produce noise, so that S/N ratio becomes lowered and distance measurement accuracy becomes lowered.